Spatially structured mesopredator suppression and release in a species-rich terrestrial carnivore assemblage
University Of East Anglia
The mesopredator release theory states that in the presence of apex predators, mesopredators are suppressed, but in their absence, mesopredators experience an increase in activity which can exert greater predation pressure on their prey. This has yet to be studied in predator rich ecosystems. This study aims to assess the how deep into the African carnivore community mesopredator suppression extends, and what effect this has on prey species lower down the trophic web.
Data were collected from Mar-June 2013 from three reserves with lions, and three reserves without lions. Track count surveys were conducted along 1km transects on dirt roads to assess the behaviour and relative abundance of the carnivore community. Species, habitat and behaviour were recorded for each track set. Rodent track tubes were placed in transects of four, and used to assess rodent behaviour and relative abundance. 70 replicates of each were conducted.
Data collection will conclude on the 15 June, therefore no results are yet available. Expected results are that activity of large and medium sized carnivores will be suppressed when lions are present, thereby benefiting small carnivores, and reducing small mammal activity. When lion are absent, large and mid-sized carnivores will increase in activity, suppressing the small carnivore community, and benefiting the small mammal community.
Across Africa, lions are being introduced to reserves for conservation and economic reasons. The full ecological impacts of these introductions are poorly understood and monitoring is often meager. This study may shed light on the potential ecological consequences of these introductions. Furthermore, this could give insight into the dynamics of other predator-rich systems, and may help inform the conservation strategies of carnivores, or their prey species.